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#apertus IRC Channel Logs

2013/12/01

Timezone: UTC


23:15
troy_s
Oh god.
23:15
troy_s
4k. 4k. 4k.
23:15
troy_s
Junk bullshit numbers everywhere.
23:15
Bertl
yeah, 4k looks completely different than 2k :)
23:16
troy_s
Such idiocy.
23:16
troy_s
Using the mythical numbers of the sunglasses-cum-camera vendor, the Panavision Genesis mark one was a 6k camera.
23:17
troy_s
The _only_ 4k camera currently on the market is the Sony F65, and I am quite certain no troll in this channel has ever touched one.
23:18
troy_s
(With perhaps an exception for rexbron)
23:25
Bertl
hehe
23:43
se6astian
time for bed
23:44
se6astian
already later than usual for me :)
23:44
se6astian
good night!
23:44
se6astian
left the channel
00:04
dmj_nova
joined the channel
00:06
dmj_nova1
left the channel
01:28
Sasha_C
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01:43
Sasha_C
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02:15
FergusL
dmj_nova: why that question about low light with higher frame rate ?
02:22
dmj_nova
FergusL: depending on what needed changing to get the higher frame rate, it might involve such a design tradeoff
02:22
dmj_nova
of course, it's also possible that the light-sensitive region is exactly the same and some other circuitry is just being clocked higher
02:23
Bertl
I doubt they changed anything except for the LVDS readout
02:23
Bertl
you can get the same framerate already for a window
02:30
FergusL
I guess it's still obivous to you that received light will be divided by two ?
02:30
Bertl
at twice the framerate at least :)
02:34
rexbron_
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02:35
rexbron
left the channel
02:45
dmj_nova
FergusL: yes, when doubling framerate recieved light will be halved
02:46
dmj_nova
my concern was mainly that the image not be noisier when framerates were equal
02:46
dmj_nova
say at 24fps with 1/48th shutter speed
02:53
FergusL
I don't get it
03:23
dmj_nova
FergusL: what don't you get?
03:24
FergusL
what do you mean by equel ?
03:24
FergusL
what is equal ?
03:34
dmj_nova
so you have the old CMV12000 and the new one
03:35
dmj_nova
Instead of pushing the new one at higher framerate, you use both with the same settings
03:35
dmj_nova
then compare the images each sensor produces
03:36
dmj_nova
do you:
03:36
dmj_nova
a) get identical images
03:36
dmj_nova
b) the new sensor produces a noiser image
03:36
Bertl
only CMOSIS can answer that
03:36
dmj_nova
Bertl: I suspect so, but it's a good question to ask
03:36
dmj_nova
was just explaining what I meant to FergusL
03:36
Bertl
go ahead, ask them
03:40
Bertl
in the time you spent today asking people the question who cannot know the answer and explaining why you think it is a good question, you could have already formulated a proper request/questions for cmosis
03:55
dmj_nova
Bertl: true
03:56
dmj_nova
troy_s: I do know some who have used the F65.
03:57
dmj_nova
I think it was used for Tears of Steel
04:07
FergusL
no, only planed to be shot on F65, was shot on Red Epic... or maybe they shot the vfx shot with F65
04:07
FergusL
still, nobody here remotely approached one
04:07
FergusL
maybe me at the AFC micro-salon where Sony has a booth !
04:08
dmj_nova
FergusL: Tears of Steel was *all* vfx shots
04:08
FergusL
sorry I meant green screen shots
04:10
dmj_nova
again, all green screen shots :P
04:10
dmj_nova
http://mango.blender.org/production/4-tb-original-4k-footage-available-as-cc-by/
04:10
dmj_nova
not claiming anyone in the channel has used it
04:12
dmj_nova
though some in #blender and #blendercoders will have
04:13
FergusL
the bridge shots were shot 2 passes too ? plate + actors
04:15
dmj_nova
FergusL: nope, bridge shots were one take, you're right on that
04:15
dmj_nova
though they do have background plates for some shots
04:16
dmj_nova
everything but the bridge is green screen or cgi though
04:17
Bertl
off to bed now ... have fun!
04:17
FergusL
same, night
08:43
guesst
dmj_nova: depends on shutter mode, if you shot 1/48 at 24 or 48 fps, the lower framerate makes higher noise in GS, in RS the output will be equal
08:47
dmj_nova
guesst: :-/kinda tired of explaining what the original question was but here goes:
08:48
dmj_nova
so CMOSIS came out with a new version of the sensor that can do up to 300 fps.
08:48
guesst
it is not public info yet?
08:49
dmj_nova
I had asked on the list whether this new version had any adverse effects on noise at the slower framerates the older version could achieve
08:49
dmj_nova
our guess is that they're just clocking the same chip higher without any changes that affect image quality, but I should ask CMOSIS to know for sure
08:51
guesst
so for that change, my answer is that it can perform better in rolling shutter mode
08:52
guesst
well, in global too.. you just get the image out quicker and gets less corrupted
08:55
dmj_nova
there is no rolling mode to my knowledge
08:56
guesst
also note, that when you run the sensor at the max speeds, you might end up with disabling some onchip noise correction..
08:56
dmj_nova
also, how does being able to shoot 150fps vs 300fps change how things look at 24 or 48 fps?
08:56
guesst
so you have just GS, that is bad
08:56
guesst
the image gets noise, especially the bottom part
08:57
dmj_nova
well, it's just the way it is :)
08:57
guesst
so with 300fps readout you get just half the noise, over 150
08:57
guesst
does not need to be :) there are sensors capable both rs/gs
08:57
dmj_nova
guesst: but you collect half the light
08:57
dmj_nova
which means using more gain
08:58
guesst
no
08:58
guesst
with 24 fps you can collect up to 1/24
08:58
guesst
but you readout the global buffer at 150 vs 300
08:58
dmj_nova
sigh
08:58
dmj_nova
no, at 150 fps, you can only have a shutter speed up to 1/150th of a second
08:59
guesst
the exposition and readout are two separete processes
08:59
guesst
and can happen at different speeds
08:59
guesst
readout >= exposition (fps)
08:59
guesst
or read time < expo time
09:00
dmj_nova
output frame interval >= exposure duration
09:01
dmj_nova
if there is a frame 150 times per second
09:01
guesst
ther is no
09:01
guesst
there is 1 frame 24 times
09:01
guesst
get out in speed of 1/150 s
09:01
guesst
vs 1/300s
09:01
dmj_nova
/facepalm
09:02
dmj_nova
think slow motion
09:02
dmj_nova
okay
09:02
dmj_nova
you shoot 150 or 300 frames every second
09:02
guesst
you shoot 24 :)
09:02
guesst
but for slowmo, there is of course loss of light
09:02
dmj_nova
the new sensor can shoot up to 300 frames every second
09:03
dmj_nova
the old one can shoot only 150 frames every second
09:03
guesst
that both applies for full 12MP res?
09:04
dmj_nova
my question was whether the new 300fps sensor would perform as well in low light at equivalent framerates and exposure times
09:04
dmj_nova
both sensors can shoot at lower framerates
09:04
guesst
so that is what i try to explain
09:05
guesst
in equal frame rate, shutter speed and gain setting, the new one could do better, given that the data receiving electronics is capable of higher speeds
09:06
dmj_nova
I'd actually guess that the electronics are exactly the same.
09:06
dmj_nova
and the only difference is that this is a new binning class
09:07
guesst
then you get no benefit, except for process variation which can make both less or more noise :)
09:07
dmj_nova
but I'm not sure if this is the case
09:07
guesst
binning like pixel merging? so you are not getting full res now? !
09:07
dmj_nova
no, not pixel merging
09:07
dmj_nova
binning is a term in semiconductor manufacturing
09:09
dmj_nova
rather than throw out chips that can't handle full clock speed or have a bad memory unit or processing core, you disable the bad components or clock them slower, then sell them as a lower model
09:09
dmj_nova
In the case of Sensors, they bin chips by the number and nature of bad pixels
09:09
guesst
i would say it is a different design
09:10
dmj_nova
so this is one of 3 things:
09:12
dmj_nova
1) they changed everything (including the light detecting region) -> could impact noise/sensitivity
09:12
dmj_nova
2) they only changed some circuitry relating to the signal transmission to handle higher clock speed -> unlikely to affect image quality
09:12
dmj_nova
3) this is a higher bin but otherwise identical -> almost certainly equal or slightly better image quality
09:13
guesst
if you can get the new sensor, you can compare it
09:13
dmj_nova
or just ask the company what they changed
09:13
guesst
are you doing some comparison agains red/arri anyway, before going to next step
09:14
dmj_nova
we couldn't compare until our next steps anyway
09:14
guesst
nothing has more value than a direct comparison :) you could not tell from the changed items if it is better or worse
09:14
dmj_nova
we're still at first images
09:14
guesst
so what is next?
09:15
dmj_nova
more advanced prototype. We need to design a processing board before we can get full speed video output
09:15
guesst
i am thinking so
09:16
dmj_nova
plus our initial images aren't calibrated or anything
09:17
dmj_nova
imagine RED footage without the dark noise calibration.
09:17
guesst
so the funding campaign is moving to next year? what do you need for the processing board?
09:17
dmj_nova
And our first sensor was defective (and therefore cheaper)
09:19
dmj_nova
so a sensor that did pass QA is necessary to test image quality too
09:19
dmj_nova
anyway, I gotta get back to work
09:20
dmj_nova
spent way to much time explaining this stupid question :P
09:20
guesst
yeah, just borrow old/new sensor of production quality and compare them yourself
10:04
philippej
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10:32
dmj_nova
philippej: good point on the lvds lines
10:32
philippej
we need to summarize all discussiobs somewhere else
10:32
philippej
it's too time consuming to follow up with everything
10:40
philippej
left the channel
10:48
troy_s
dmj_nova: No big thrill here. ;)
10:48
dmj_nova
what thrill?
10:48
troy_s
ToS was all F65, but boy was post porked.
10:50
troy_s
The overall FPS has no impact.
10:50
troy_s
(aside from the higher FPS)
10:51
troy_s
dmj_nova: Of being around an F65.
10:51
troy_s
Not exactly thrilling here.
10:52
dmj_nova
post porked?
10:52
dmj_nova
You mean that most everything is CGI?
10:57
troy_s
I mean the pipeline was... a little odd.
10:58
dmj_nova
ah, yeah I recall some of that
10:59
dmj_nova
format conversions, funny colorspaces and such
10:59
troy_s
At the time it still hadn't set in what I had been harping on about primaries and such.
10:59
troy_s
There is so much of a knowledge gap regarding color etc.
10:59
troy_s
And scene referred versus display referred etc.
10:59
dmj_nova
yeah
11:00
troy_s
There are _still_ some folks that would like to insist that “linear” is a color space.
11:00
troy_s
Which drives me bloody batty.
11:00
dmj_nova
hehe
11:01
dmj_nova
though to be fair, linear is about all 3D rendering can or should care about
11:01
dmj_nova
the algorithms kinda need it to be that way
11:01
dmj_nova
of course what you do from that linear output is different
11:02
troy_s
I remember when they were sitting on the F65 footage and didn't know what to do with it.
11:02
troy_s
I demoed how to process it via OCIO.
11:02
troy_s
Linear is vastly more important than that.
11:03
troy_s
Both display linear and scene linear is the _only_ way to correctly blend light.
11:03
dmj_nova
yes, that's what I meant
11:03
troy_s
So even a dissolve is screwed if you aren't in a display or scene linear model.
11:03
dmj_nova
You need linear to "add" light
11:03
troy_s
Add, blend, multiply, anything really.
11:04
troy_s
Aside from a timed dissolve that appears perceptually timed.
11:05
philippej
joined the channel
11:05
troy_s
But the linear side (either scene or display) is only one half of the issue. The other half - the primaries (or color essentially) is equally important.
11:06
troy_s
And all of this is inevitably crap that people have to learn on the road to attempting what appeared so simple when they started (programming a decoder, player, etc.)
11:07
troy_s
It is always why I giggle and sigh when I read people wanting to add “simple grading” to an application and yet they haven't even begun to figure out color.
11:09
dmj_nova
sounds like something that should be documented for such people
11:10
troy_s
It is a path of pain and nightmare.
11:10
troy_s
Not worth it. No one would ever attempt it. Hence why I chuckle at some of the libraries.
11:11
troy_s
Prudent to stick to the industrial ones and then figure out why.
11:12
dmj_nova
no one would ever attempt documenting it?
11:13
troy_s
Most of the time the information is out there. Many are often stubborn or unwilling.
11:13
troy_s
Which can be positive as well I suppose.
11:14
troy_s
Selan's document is wonderful.
11:14
dmj_nova
link?
11:19
guesst
so is apertus more about hardware or software?
11:25
troy_s
guesst: A camera is both.
11:25
troy_s
Unavoidable byproduct.
11:25
dmj_nova
you can't build a functional piece of hardware without software to make it run
11:25
troy_s
dmj_nova: http://cinematiccolor.com
11:25
philippej
left the channel
11:26
dmj_nova
we're building a hardware device, but software is needed to make it do stuff
11:27
guesst
so the primary goal is to make a camera, and the rest is just to make use of it
11:27
guesst
i was thinking for a moment that you are doing software as primary and a camera is unavoidable as so far there are none to use
11:30
dmj_nova
no, the project is about making the camera
11:31
dmj_nova
there may be software projects out there for with the axiom is beneficial because there aren't equivalents, but it's apertus' business to develop the thing
11:32
troy_s
guesst: Not sure I would divide the goal into a metric of primary / secondary. The model is broken
11:32
troy_s
A functional camera consists of software and hardware. Unavoidable.
11:33
troy_s
Simply parts of a whole
11:33
guesst
i meant camera(hw/sw) vs. digital cinema toolchain
11:33
troy_s
guesst: Well processing images has to take the pipeline into account.
11:34
troy_s
Again, unavoidable. Or rather, if you avoid / ignore it, the byproduct is a sub-optimal design often (audience depending)
11:36
guesst
for me it seems already suboptimal by trying to cover all those aspects
11:38
dmj_nova
if you don't bother to characterize your colorspace you'll be unsuitable for many uses
11:43
dmj_nova
huh, this chart has suddenly helped me understand why I grade images the way I do.
11:43
dmj_nova
S-curve
11:47
Bertl
morning everyone!
11:57
dmj_nova
troy_s: that article is great
12:02
Sasha_C
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12:35
se6astian
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12:36
se6astian
hello!
12:36
Sasha_C
Hi Se6astian. What's news?
12:37
se6astian
not much I guess :)
12:38
Sasha_C
I've been reading up on the logs in our archives. I didn't realise so much stuff was happening whilst I was asleep :(
12:42
se6astian
:)
12:44
dmj_nova
se6astian: so that nofilmschool article seemed not to understand what it was talking about
12:46
Sasha_C
dmj_nova: That wouldn't be the first time this has happened ;)
12:46
Sasha_C
left the channel
12:46
dmj_nova
thinking that a camera that is likely limited by processing or storage limits will become faster based on a sensor upgrade
12:46
Sasha_C
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12:47
dmj_nova
Sasha_C: thinking that a camera that is likely limited by processing or storage limits will become faster based on a sensor upgrade
12:49
guesst
they just might lower the noise and make something with the black spots in brigth areas :)
12:50
guesst
dynamic range of 60dB equals to 10bit / 10stops, right?
12:50
Bertl
the 'black sun' artefacts
12:51
guesst
yes
12:51
guesst
was looking on IBC for them.. they got it :P
12:52
dmj_nova
'black sun' artifacts?
12:54
guesst
when you apply extremely high light input to a sensor, it corrupts the referenced value and the conversion leads to usually dark / black pixel, but can be random
12:55
guesst
http://vimeo.com/52965171
12:56
guesst
anyway it is not much adviced to point it to sun.. you might vaporize the color filter :)
12:56
guesst
but on ibc we turned the camera up to the ceiling - to sharp lights and it was there too
13:02
se6astian
most sensors have settings related to dark spot sun supressions
13:02
se6astian
so does the cmv12000
13:02
se6astian
anyway, gotta go :)
13:02
se6astian
see you later
13:02
se6astian
left the channel
13:02
Sasha_C
caio
13:48
Sasha_C
left the channel
14:17
Bertl
test 1 2 3
14:32
FergusL
Bertl we copy, ove
14:32
FergusL
r
14:49
Bertl
hehe
15:01
ThatCantBe
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16:08
Bertl
off for a nap ... bbl
16:27
se6astian
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16:29
se6astian
good evening
18:24
ThatCantBe
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19:37
Bertl
back now ...
20:11
philippej
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20:22
philippej
Hi everyone
20:53
FergusL
'evening there
20:53
philippej
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22:29
se6astian
good night!
22:29
se6astian
left the channel
23:02
troy_s
guesst: Sub optimal to cover them? Yes if you think building software. But you need to think harder.
23:02
troy_s
guesst: Things like codecs for editorial, file formats for online, etc. are all dreadfully imoortant.
23:03
troy_s
guesst: _Every_ design choice is non-neutral and comes with very particular implications for worlflows.
23:06
theverant
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23:08
Sasha_C
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